BQ25887: BQ25887 Reverse Cell Protection

Sean Kovacs

Part Number: BQ25887

I see that the BQ25887 has reverse cell protection based on a resistor between IC MID and middle point of 2 cell setup.

When connecting any 1 cell in reverse, the IC heats up incredibly. I only leave it like this for 1 or 2 seconds in fear the IC will destroy itself.

Is this normal?

over 1 year ago

0 Michael Emanuel35 over 1 year ago

TI__Mastermind 32455 points

Hello,

This protection exists only for bottom cell. There is a conduction path through the device that will generate heat. However, if other components in the system are not protected against this reverse battery further heating and/or stress to the system could occur.

Regards,

Mike Emanuel

0 Sean Kovacs over 1 year ago in reply to Michael Emanuel35

Prodigy 110 points

Hello Michael. Thank you. So are you suggesting that the IC will in-fact be fine if the 2 cell series is in backwards?
Instead of the expected batteries [+ -] [+ -], the batteries are [- +][- +] ?

0 Michael Emanuel35 over 1 year ago in reply to Sean Kovacs

TI__Mastermind 32455 points

It reads in the pin description as, "For protection of bottom cell reverse plug in, connect a 300 ohm resistor in series between MID pin and mid connection point of the two battery cell." It only functions for bottom cell reverse plug in.

Regards,

Mike Emanuel

Power management

Power management forum

BQ25887: BQ25887 Reverse Cell Protection